look up any word, like fleek:
 
1.
to push it to the limit. to see how far you can go with something without getting caught.
Whoa she pushes the envelope in her risque music videos.
 
2.
"stretch the limits" - to go further (in any field) than anyone or any group has done before. perhaps doing something that wasn't previously thought possible.
dude, that quadruple-backflip double-twist one-handed going backwards while blindfolded and sucking a lolly (deep breath) surf manoeuvre was really pushing the envelope.
by Smiff November 03, 2003
 
3.
To outdistance everyone else in an activity - set a new standard or precedent
by Anonymous November 03, 2003